1. Field of the Invention
The present invention relates to a toe angle controller which controls toe angles of rear wheels of a vehicle.
2. Description of the Related Arts
A technique is disclosed for a vehicle including a four-wheel independent steering system provided with toe angle controllers for the left and right rear wheels respectively to control the toe angles of the left and right rear wheels independently based on the steering angle of steered wheels and a vehicle speed, etc. The four-wheel independent steering system controls four wheels independently including front wheels (Refer to patent document 1, for example).
In such a vehicle, a control unit, which independently calculates target toe angles to be set to the left and right rear wheels, is provided to the toe angle controllers. The control unit transmits as command values the target toe angles to actuators which can independently turn the left and right rear wheels to turn the rear wheels and set the toe angles of the rear wheels.
Patent Document 1: Japanese Patent Publication No. 06-47388 (FIG. 2)
However, in the technique disclosed in the Patent Document 1, a case is not taken into consideration in which the output of an actuator provided to one of the toe angle controllers is insufficient and the turning amount of one of the rear wheels becomes insufficient. If the turning amount is insufficient, the toe angle of the rear wheel can not be set to be the target toe angle calculated by the control unit, which deteriorates the motion performance of the vehicle.